battery

Abstract

Disclosed herein is an aqueous Zn ion battery, AZIB, comprising: a stainless steel current collector; a cathode; a solid Zn ion separator; an anode; a Cu film current collector; and an aqueous electrolyte of mixed trifluoromethanesulfonic zinc (Zn(CF3SO3)2) and trifluoromethanesulfonic manganese (Mn(CF3SO3)2).

Description

[0001] Battery

[0002] Field

[0003] The invention relates to the technical field of energy storage devices, in particular to the thick cathode and anode electrodes and solid Zn ion separator for aqueous zinc ion batteries with high energy density and preparation methods thereof.

[0004] Background

[0005] The EU has stated its ambitious goal of having more than half of Europe run on renewable energy by 2030. By 2050, the share of electricity in the final energy demand is expected to be more than 80 percent. Renewables would have to be stored for later use to provide a power supply during excess energy demands. The storage process can be done on the grid and individual building levels, which has made Europe a renowned home of energy storage technologies. Driven by the ongoing clean energy transition, demand for batteries is expected to grow very rapidly in the coming years. According to some sources, the European battery market of potential could be worth up to EUR 250 billion annually from 2025 onwards. The role and importance of energy storage, and in particular battery storage technologies, is set to increase significantly. In the medium-term, stationary batteries are expected to reach about 10 percent of the battery market, but their role will grow further. In the 2050 perspective, stational storage will become the principal way of integrating renewables into the power system, which is expected to play a far more significant role than pumped hydro storage technology.

[0006] Of the next-generation batteries, zinc-ion batteries (ZIBs) show several advantages related to Zn, including high abundance, high theoretical gravimetric / volumetric capacity (820 mAh / g, 5855 mAh / cm3), ultimately cheaper (~$2.4 US kg ') than Li (~$19.2 US kg1), impressive electrochemical stability and reversibility in water, high energy and power density, the intrinsic safety, and low toxicity bring the ZIB technology to the best candidate to replace Li-ion battery in stationary energy storage. In addition, the low cost and high energy and power density of Zn ion batteries make ZIB attractive for replacing the lead acid battery. The low redox potential of the Zn / Zn2+couple (- 0.76 V vs. SHE) makes the Zn ion battery suitable for the aqueous electrolyte. In addition, Zin is 100 times more abundant and cheaper than lithium. Zn is highly abundant, and 12000 kilo tons of Zn are produced in the world, which is not limited to producing enough Zn ion batteries covering the whole storage market. Rechargeable aqueous Zn-based EES devices (AZDs) have proven to be promising candidates in multiple application scenarios. Compared with nonaqueous systems, aqueous electrolytes possess certain attractive features, including (1) higher ionic conductivity (1 - 100 S nr1) compared with organic electrolytes (IO-6- 10'3Snr1), such as one n KOH (18.4 Snr1), thus providing higher power densities and fast-charging capabilities, (2) minimized potential risks due to low-volatile, non-toxic, and non-flammable characteristics, (3) lower manufacturing costs by excluding oxygen-free and drying production lines, and (4) high tolerance against electrical and mechanical mishandling.

[0007] In spite of the clear advantages of ZIBs, the low energy density of battery cells (<40 kwh / g), low cycle stability, and a high potential for hydrogen generation hindered its large-scale commercialization. Zn has been used as an active electrode in the development of energy storage devices since 1800. The Zn-MnCh battery with KOH electrolyte was first commercialized in 1952. However, no significant achievements were made until 2009. Kang and co-workers introduced the concept of rechargeable Zn-ion battery (ZIB) in 2009, and 2012. Moreover, the previous zinc chemistries have struggled to deliver on power, size, and rechargeability.

[0008] Although aqueous Zn ion batteries (AZIBs) have attracted extensive attention because of their advantages of low price, high safety, and high power density, the utilization of Zn metal anode remains challenging. In one aspect, most of the present research adopts Zn metal foil, Zn metal powder, or electrodeposited Zn as the anodes. The critical challenge is that the discharge depth and Zn metal utilization are usually low, meaning that the efficiency of Zn utilization and the excessive Zn anode must be used, which will lower actual gravimetric and volumetric specific capacity. In another aspect, dendrite growth, low plating / stripping efficiency, and complex side reactions of Zn metal anode severely deteriorate battery life and performance, even causing safety issues. The anode-electrolyte interface is often accompanied by some harmful problems that hinder the performance of AZIBs. Due to the uneven distribution of the electric field and Zn2+concentration field, dendrite growth often exists on the Zn anodes, causing the battery to short circuit. In addition to Zn dendrites, another big issue on Zn anodes is the side reactions (hydrogen evolution reaction (HER), corrosion, and passivation) driven by the thermodynamic activity of Zn metal in an aqueous solution. The side reactions could reduce Zn utilization and the columbic efficiency (CE) of the Zn plating / stripping on Zn anodes.

[0009] Manganese-based materials are the most often used cathode materials since Mn is 10th most abundant element in the earth and environmentally friendly, with variable oxidation states (+2, +3, +4, and +7), (iii), in addition they have suitable crystal structure for the reversible intercalation / de- intercalation of Zn2+. Recent studies found that a reversible two-electron Mn4+ / Mn2+redox reaction (~600 mAh g1vs the normal 308 mAh g 'for Mn4+ / Mn3+). A liquid-solid conversion from MnCh to Mn2+is expected to create a rechargeable battery with a higher reliability. However, they suffer from dissolution- related issues, which adversely affect the cycling performance of the device. There has been a lot of efforts to stimulate the Mn4+ / Mn2+redox reaction and stable the electrode, such as triggering a highly reversible MnCh / Mn2reaction and adjust manganese concentration in deposition / dissolution process by the acetate anion, bentonite colloidal (Ben-colloid) electrolyte.

[0010] In addition, for the practical applications of aqueous ZIBs, high specific energy and energy density are essential. Increasing the mass loading per area of active compounds in the cathode and anode is necessary to increase the area capacity. The conventional manufacturing methods, such as the casting of battery slurry, result in a very thick electrode and low capacity and energy density. Therefore, it is valuable to design and fabricate free-standing cathodes with low cost, high areal capacity, and high-rate capability, as well as long-term durability

[0011] Summary

[0012] Aspects of the invention are set out in the appended independent claims.

[0013] List of Figures

[0014] Figure 1(a) shows charge and discharge curves of the Zn-MnCh zinc ion battery, according to embodiment 1, with PPS solid separator film coated by PVA-carbon at C / 8 for 10 cycles. The energy efficiency is up to 88 %.

[0015] Figure 1(b) shows the cycling performance of the zinc ion battery, according to embodiment 1, at C / 8 and C / 4. Figure 2(a) shows charge and discharge curves of Zn-P-MnO? zinc ion batery for at 1C over 2000 cycles.

[0016] Figure 2(b) shows the long-term cycling performance of the Zn-P-MnCh zinc ion battery at 1 C, the capacity retention is up to 80%.

[0017] Figure 3 shows the change of areal capacity with the increase of loading thickness on one-side MnCh cathode.

[0018] Figure 4 shows the cycling performance and coulombic efficiency of the Zn-P-MnCh zinc ion battery with 2 M ZnSCE and 0.1 M MnSCE electrolyte.

[0019] Description of Embodiments

[0020] Embodiments of the present invention provide an aqueous zinc-ion battery that may have a high- energy capacity and long-lifespan. The batery may comprise a thick MnCE-carbon cathode and dendrite-suppressing solid zinc ion separator.

[0021] Embodiments provide an aqueous zinc-ion battery designed for high energy density and extended operational longevity. The battery may comprise a thick manganese oxide-carbon (MnCE-C) composite cathode and a zinc powder-carbon composite anode, both of substantial electrode thickness to boost area capacity. The battery comprises a thin, robust solid zinc ion separator which ensures uniform ion diffusion and significantly mitigates dendritic growth, a common issue that plagues the lifespan and safety of batteries. The strategic composition of the electrode materials finely adjusts the in-situ concentrations of Mn2+and Zn2+ions, curtailing hydrogen evolution and other deleterious side reactions. This results in a batery system that not only achieves high energy storage capabilities but also maintains structural and electrochemical integrity over numerous charging cycles. The disclosed preparation methods further contribute to the practical and scalable production of these energy storage devices.

[0022] Embodiments of the present invention provide manganese oxide-carbon cathode electrodes with a high area loading of the active materials through thick and dense electrodes, which have a thickness of 50-200 pm, a packing density of 1.5-2.5 g / cm3(preferably a packing density of 2.0-2.5 g / cm3, and more preferably a packing density of 2.2-2.5 g / cm3) to enhance the area capacity and energy density. The cathode electrodes may comprise, and optionally consist, of manganese oxides and conductive carbon materials, bentonite, cellulose fiber and PTFE as a binder and the mixed mass ratio of the manganese-based oxide, conductive carbon materials / betinate, cellulose fiber and PTFE is 70%-95%: 0%-20%: 0%-10%: 3%-l 0%. The conductive carbon material is any one or a combination of the following materials: N doped carbon, acetylene black, activated carbon, graphite acetylene black. The shape of the activated carbon materials is preferred to be fibers and spheres. The cellulose fibers are any one or a combination of following materials: cellulose nanofibers and microfibers. The cellulose fibers endow the material with sufficiently high stiffness to fabricate self-standing films, and enhance the mechanical strength. The fibrous polytetrafluoroethylene PTFE, and spheric-shaped highly porous carbon materials enhance the ion diffusion. In addition, the intrinsic capacity is enhanced by an ion concentration / dilution strategy to trigger the extra deposit! on / dissoluti on capacity of the Mn4+ / Mn2+redox reaction in normal Zn / MnCh batteries. With the precipitation and release of Zn2+ions during the discharge / charge process, manganese concentration, and thus also pH value, is successfully stabilized via the reciprocal Zn / Mn ionic exchange rendered by the high surface area of active carbon, more preferred N-doped carbon. Preferably, the positive active material is any one or a combination of the following positive electrode materials: manganese-based oxide, polyaniline; the conductive carbon material is any one or a combination of the following: N doped carbon, acetylene black, activated carbon, Graphite; the binder is polytetrafluoroethylene PTFE.

[0023] Embodiments provide Zn powder-carbon anode electrodes with a high area loading of the active materials by using thick and dense electrodes, which have a thickness of 50-200 pm, and a packing density of 1.5 -2.5 g / cm3(preferably a packing density of 2.0-2.5 g / cm3, and more preferably a packing density of 2.2-2.5 g / cm3), to enhance the area capacity and energy density. It greatly enhances Zn utilization. The close contact of Zn powders with carbon materials regulates the desolvation of [Zn(H2O)e]2+and Zn deposition kinetics, thus suppressing dendrite formation and hydrogen formation.

[0024] The anode electrodes may comprise, and optionally consist, of Zn powder and conductive carbon materials, cellulose fibers, and PTFE as a binder and the mixed mass ratio of the Zn powders, conductive carbon materials, cellulose fibers and PTFE is 70%-95%: 0%-20%: 0%-10%, 3%- 10%. Embodiments provide thick cathode and anode electrodes in the electrolyte of the mixed zinc trifluoromethanesulfonate (Zn(CF3SO3)2) and manganese trifluoromethanesulfonate (Mn(CF3803)2). The mixed electrolyte has not only the high ionic conductivity and electrochemical stability of (Zn(CF3SO3)2) but also leads to the in-situ formation of ZnF2 on the surface of Zn powders, which serves as a multifunctional protective layer. It reduces the desolvation active energy of [Zn(H2O)e]2+significantly, leading to stable and facile Zn deposition kinetics and lowering hydrogen generation.

[0025] Embodiments include the provision of an asymmetric solid separator consistent with a multilayer structure, such as PE / PPS / cellulose film. Both PE and cellulose film have a thickness in a range of 5-10 pm, and PPS film is in a range of 15-20 pm, with a low porosity (<5%). The PPS films are prepared by the mixed pre-zincified polyphenylene sulfide powder, cellulose fibers, and polytetrafluoroethylene (PTFE) powders.

[0026] The preparation method of the pre-zincified polyphenylene sulfide solid membrane separator is as follows: the mixed pre-zincified polyphenylene sulfide powder, cellulose fibers, and polytetrafluoroethylene powder are oriented and heated in supersonic dry airflow. Pressing into a film to prepare the pre-zincified polyphenylene sulfide solid electrolyte membrane. The solid membrane has very low porosity (<3%), and selective transport Zn ions, instead of molecules of electrolytes.

[0027] Embodiments also provide the dry process method to prepare separators and electrodes. It includes the fiberization of the PTFE of electrodes using high-speed alloy blades under freezing conditions; the thickness of the film is about 100 pm, and the density is 2.2 g cm’3.

[0028] Embodiments 1 to 5 are described below.

[0029] Embodiment 1

[0030] This embodiment provides a method for preparing a zinc ion battery, which specifically includes the following steps:

[0031] 1) Preparation of thick cathode electrode

[0032] Mixed powders of Mn2O3 (commercial powders), commercial activated carbon and binder PTFE in a ratio of 91:3:6 are oriented and heated in a supersonic dry airflow, where the PTFE is sufficiently fiberized, following adding alcohol and water, then centrifuge to remove excess liquid and pass through a roller press at room temperature. It is then pressed into a self-supporting film.

[0033] The thickness of the film is 100 pm, and the packing density of the film is 2.5 g / cm3.

[0034] 2) Preparation of thick anode electrode

[0035] Mixed powders of Zn (commercial powders), commercial activated carbon and binder PTFE in a ratio of 74:20:6 are oriented and heated in a supersonic dry airflow, following adding alcohol and water, then centrifuging to remove excess liquid, and passing through a roller press at room temperature. It is pressed into a self-supporting film. The thickness of the film is 100 pm, and the packing density of the film is 2.5 g / cm3.

[0036] (3) Preparation of zinc solid separator:

[0037] Pre-zincified polyphenylene sulfide powder, cellulose fiber, and PTFE powder are mixed according to the weight percentage of 91%:3%:6%, and the PTFE in the mixture is sprayed in the PTFE directional drawing equipment by using 45 °C preheated compressed air with an airflow rate of supersonic speed. The fibered powder was extruded to prepare the pellets. The pellets were injected into the rolling machine in three steps. At the first step, the pellets were pressed into a continuous phase at room temperature. Following this, at the second step, they were pressed into thin films at 50°C in a thickness range of 500-700 pm. At the third step, and free standard films with a thickness of 15 pm were prepared by the hot press at 145 °C.

[0038] Glue was spinned into the polyethylene layer and cellulose films with 5 pm thickness, respectively. The above mentioned two films are laminated together with the PPS films with a thickness of 15 pm in the middle to form PE / PPS / cellulose asymmetric solid separator. The laminated separator was dried in the oven with hot air at a temperature range of 60-80 °C.

[0039] 4) Preparation of electrolyte

[0040] 14g of trifluoromethanesulfonic acid was drop-wisely added into 7g of deionized water in an ice bath. Afterward, 3-5g of ZnO was gradually added with stirring and dissolved. ZnO was slightly oversaturated and formed a milky white suspension. 0.2g MnSC>4 was dissolved in ImL of water to form a solution. The solution was then added to the above white suspension with well-stirring. After filtration and centrifugation, the aqueous electrolyte of mixed Zn(CFs 863)2 and Mn(CF3863)2 was obtained.

[0041] 5) Preparation of laminar structure of cathode electrode and stainless-steel films

[0042] The free-standing positive film obtained in step (1) was dried in a vacuum and then heated to stainless steel foil as a current collector and rolled at high pressure to form a laminar structure.

[0043] 6) Preparation of laminar structure of anode electrode and Cu films

[0044] The free-standing anode film is dried in a vacuum and then heated to Cu foil as a current collector and rolled at high pressure to form a laminar structure.

[0045] 7) Assembly of zinc ion battery:

[0046] The sandwich structure of the laminar structure of the cathode from step 5, the zinc ion solid separator, and the laminar structure of the anode from step 5 are assembled. The tabs on the sandwich structure are welded, packaged into the shell, and assembled into an unfilled battery. Aqueous electrolytes comprising 2 M Zn (CFsSCh^ and 0.1M Mn((CF3SO3)2, vacuum and seal to form the zinc ion battery.

[0047] Figure 1(a) shows charge and discharge curves of the Zn-MnCh zinc ion battery, according to embodiment 1, with PPS solid separator film coated by PVA-carbon at C / 8 for 10 cycles. The energy efficiency is up to 88 %. The x-axis (labelled X) in Figure 1(a) shows Capacity Density in the units mAh / g. The y-axis (labelled Yl) in Figure 1(a) shows Voltage in the units V.

[0048] Figure 1(b) shows the cycling performance of the zinc ion battery, according to embodiment 1, at C / 8 and C / 4. The x-axis (labelled X) in Figure 1(b) shows the cycle ID / number. The y-axis (labelled Yl) in Figure 1(b) shows the Specific Capacity -Dchg.

[0049] The performance of the Zn-Mn02 zinc ion battery was carried out and the performance is presented in Figures 1(a) and 1(b). The voltage window is 1.9-1.0 V. The specific energy is about 140 mAh / g. The battery is stable during the cycles tested.

[0050] Embodiment 2 In embodiment 2, all the steps are similar to, or the same as, the steps described for Embodiment 1, except for the differences explained below.

[0051] Preparation of zinc ion solid separator: The procedure is similar to Embodiment 1 step 3, except that, in this embodiment, Pre-zincified polyphenylene sulfide powder, and PTFE powder are mixed according to the weight percentage of 94%: 6%.

[0052] The Zn ion conductivity is measured by a multichannel constant potential instrument (PARSTAT MC ™, AMETEK).

[0053] The measure of the Zn ion conductivity of the solid Zn ion separator without cellulose fiber prepared in Embodiment 2 is 5.62* 1 O'3S / cm’1, higher than the one prepared in Embodiment 1, step 3 (which was 1.32*1 O'3S / cm'1).

[0054] Embodiment 3

[0055] All the steps are similar, or the same, as described for Embodiment 1, except for the differences explained below.

[0056] The preparation of the free-standing -MnCh based cathode film comprises mixing powders of 0- MnCh (hydrothermal synthesis), N-doped activated carbon spheres, and binder PTFE in a ratio of 91:3:6 for ultra-vacuum drawing, then adding alcohol and water for tanning, then centrifuging to remove excess liquid, and passing through a roller press at room temperature It is pressed into a self-supporting film.

[0057] SEM images of cross section of cathode show that the PTFE has a fibrous structure and forms a fibrous network in the cathode film. The MnCh powders are embedded inside the fibrous network. A tangle network structure is formed by the fibrillation of the PTFE.

[0058] Figure 2(a) shows charge and discharge curves of Zn- -MnCh zinc ion battery for at 1C over 2000 cycles. The x-axis (labelled X) in Figure 2(a) is in the units mAh / g. The y-axis (labelled Yl) in Figure 2(a) shows Voltage in the units V.

[0059] Figure 2(b) shows the long-term cycling performance of the Zn- -MnCh zinc ion battery at 1 C, the capacity retention is up to 80%. The performance of the Zn-Mn02 zinc ion battery was carried out and the performance is presented in Figures 2(a) and 2(b). The remaining the specific energy is larger than 80% after 2000 cycles. The coulombic efficiency was kept larger than 99.7% after 2000 cycles.

[0060] Embodiment 4

[0061] All the steps are similar, or the same, as described for Embodiment 1, except for the differences explained below.

[0062] The method for preparation of free-standing MnCh powder-based cathode film is identical to the embodiment step 1. The thicknesses of the films are 14.1, 16.1, 18.9,19.7, 22.1, 45.4, 47.0, 51.9, 60.3, 63.6, 68.4, 79.4, 97.1 123.2, 148.3 and 190.0 pm. The density of the film is 2.2. The areal capacity increased linearly with thickness of the electrode up to 148 pm. It suggests that the specific capacity (mAh / g) kept constant for the thick electrodes up to about 150 pm.

[0063] Figure 3 shows the change of areal capacity with the increase of loading thickness on one-side of the MnCh cathode.

[0064] Embodiment 5

[0065] All the steps are similar to, or the same, as described for Embodiment 1 , except for the electrolyte used here is 2 M ZnSC>4 and 0.1 M MnSC The performance of the cell is measured and compared to the performance in Embodiment 1. The results (Figure 4) clearly show that both the columbic efficiency and the capacity are lower than the one shown in Figure 1 using Zn(CF3SOs)2 and Mn(CFsSO3)2 mixed electrolyte. The columbic efficiency is between 98-88% using the 2 MZnSC>4 and 0.1 M MnSCE electrolyte. More importantly, the stability of battery cell using the electrolyte of 2 M ZnSC>4 and 0.1 M MnSC>4 (Figure 4) was much worse compared to the cell using Zn(CF3SO3)2 and Mn(CF3SO3)2 .

[0066] Figure 4 shows the cycling performance and coulombic efficiency of the Zn-P-MnCh zinc ion battery with 2 M ZnSC>4 and 0.1 M MnSC>4 electrolyte. The x-axis (labelled X) in Figure 4 shows Cycle ID / number. The left y-axis (labelled Yl) in Figure 4 shows Specific Capacity-Dchg. The right y-axis (labelled Y2) in Figure 4 shows Chg / DChg Efficiency.

[0067] The anode electrodes after 2000 cycle in Zn(CFsSO3)2 and Mn(CFsSO3)2 mixed electrolyte were analyzed by SEM and XPS to rationalize the effects of the electrolyte. The SEM images indicated the clean surface of the electrode, suggesting that the dendrite formation was effectively suppressed. XPS spectra suggested that ZnF2 was formed in-situ during the charging and discharging. The formed surface possibly suppressed the dendrite formation and water splitting, and thus a higher coulombic efficiency.

[0068] Embodiments include the following numbered clauses:

[0069] 1. Aqueous Zn ion battery (AZIB) comprises stainless steel current collector, thick cathode, asymmetric solid Zn ion separator, thick anode, Cu film currently collector, aqueous electrolyte of mixed trifluoromethanesulfonic zinc (Zn(CF3SO3)2) and trifluoromethanesulfonic manganese (Mn(CF3803)2 ), and shell.

[0070] 2. The battery according to clause 1, consists of an anode of a free-standing film, which comprises Zn powders, carbon materials, additive materials, and polytetrafluoroethylene (PTFE) with a thickness of 50-200 pm, a density of 1.5-2.5 g / cm3(preferably a packing density of 2.0-2.5 g / cm3, and more preferably a packing density of 2.2-2.5 g / cm3), the preferred thickness of 100-150 pm, more preferred thickness of 130-150 pm and a density of 2.2-2.5 g / cm3.

[0071] 3. The battery according to any preceding clause, wherein the anode electrodes consist of Zn powders, conductive carbon materials, additive materials, and PTFE as a binder, and the mixed mass ratio of Zn powders, conductive carbon materials, additive materials, and PTFE as a binder is 70%-95wt%: 0%-20wt%, 0-5wt%: 3%-10wt%, where the conductive carbon material is any one or a combination of the following materials: N doped carbon, acetylene black, activated carbon, graphite acetylene black, preferred N doped carbon spheres (10-15wt)%. The shape of the activated carbon materials is preferred to be fibers and sphere; the additive material is any one or a combination of the following materials: bentonite, polymer gel, cellulose fibers and electrolytes, and the preferred bentonite 3- 5wt%. 4. The battery according to any preceding clause, comprising a free-standing cathode film, which comprises MnCh powders, carbon materials and fibrous PTFE, with a thickness of 50-200 pm, a density of 2-2.5 g / cm3, the preferred thickness of 100-150 pm, the more preferred thickness of 100-150 pm and a density of 2.2-2.5 g / cm3.

[0072] 5. The battery according to any preceding clause, wherein the cathode electrodes consist of manganese oxides and conductive carbon materials, bentonite and PTFE as a binder and the mixed mass ratio of the manganese-based oxide, conductive carbon materials, additive materials and PTFE is 70%-95%: 0%-20%: 3%-10%, where the conductive carbon material is any one or a combination of the following materials: N doped carbon, acetylene black, activated carbon, graphite acetylene black, preferred N doped carbon spheres (10- 15wt)%. The shape of the activated carbon materials is preferred to be fibers and spheres; the additive material is any one or a combination of the following materials: bentonite, polymer gel, cellulose fibers and electrolytes, and preferred bentonite 3-5wt%.

[0073] 6. The battery according to any preceding clause, wherein preparation comprises: mixing Zn powders (for the anode) or MnCh powders (for cathode), conductive carbon powders and PTFE powders are oriented and drawn in a supersonic dry airflow to fiberize PTFE, following adding alcohol and water, then centrifuging to remove excess liquid, and passing through a roller press into a self-supporting film at room temperature.

[0074] 7. The battery according to any preceding clause, comprising a free-standing zinc ion separator film, which consists of pre-zincified polyphenylene sulfide powder, cellulose fiber, and PTFE powder with a weight ratio of 80-95%: 2-5%: 3-6%, the preferred ratio of 90-92%: 3-4%: 4-5%; the thickness is 13-45 pm, the preferred 15-20 pm; and the porosity of the film is less than 2-5% and preferred less than 3%.

[0075] The battery according to any preceding clause, wherein the preparation method comprises: mixing pre-zincified polyphenylene sulfide powders, cellulose fibers, and polytetrafluoroethylene (PTFE) powders are oriented and drawn in a supersonic dry airflow, and then hot pressed into a free-standing film at a temperature range of 120-150 °C, and preferably 130-145 °C. The thickness is in a range of 10-20 pm, and preferred 12-16 pm.

[0076] 8. The battery according to any preceding clause, wherein the asymmetric separator consists of a multilayer structure, with PE / PPS / Cellulose layers, where the thickness of the porous PE and cellulose layers are in a range of 5-9 gm, and preferred in a range of 5-6 pm; PE and cellulose films are porous and PPS film is nonporous.

[0077] 9. The battery according to any preceding clause, comprising an aqueous electrolyte that comprises a mixed solution of 1-3M Zn(CF3SO3)2 and 1-2 M (Mn(CF3SO3)2, preferred 2MZn(CF3SO3)2 and 1 M (Mn(CF3SO3)2.

[0078] The foregoing embodiments are only to illustrate the technical ideas and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement them accordingly, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

Claims1. An aqueous Zn ion battery, AZIB, comprising: a stainless steel current collector; a cathode; a solid Zn ion separator that is nonporous; an anode; a Cu film current collector; and an aqueous electrolyte of mixed trifluoromethanesulfonic zinc (Zn / CEsSChh) and trifluoromethanesulfonic manganese (Mn / CEsSChh); wherein: the cathode comprises a mixture of at least manganese oxide(s) and carbon materials, the thickness of the cathode is in the range of about 30 pm to 200 pm, and the density of the cathode is 2.0-2.5 g / cm3; the anode comprises a mixture of at least zinc powder and carbon materials, the thickness of the anode is in the range of about 30 pm to 200 pm, and the density of the anode is 2.0- 2.5 g / cm3.

2. The AZIB according to claim 1, wherein the solid Zn ion separator is asymmetric.

3. The AZIB according to claim 1 or 2, further comprising a shell.

4. The AZIB according to any preceding claim, wherein the thickness of the cathode is in the range of about 50 pm to 150 pm.

5. The AZIB according to any preceding claim, wherein the thickness of the anode is in the range of about 50 pm to 150 pm.

6. The AZIB according to any preceding claim, wherein the anode comprises, and optionally consists of, a free-standing film; and the free-standing film comprises the Zn powders, the carbon materials, additive materials, and polytetrafluoroethylene (PTFE),and the free-standing film has a preferred thickness of 100-150 pm, and a more preferred thickness of 130-150 pm.

7. The AZIB according to any preceding claim, wherein the anode comprises, and optionally consists of, the Zn powders, the carbon materials that are conductive carbon materials, additive materials, and PTFE as a binder; and the mixed mass ratio of the Zn powders, conductive carbon materials, additive materials and PTFE is 70%-95wt%: 0.5%-20wt%: 0.5-5wt%: 3%-10wt%.

8. The AZIB according to claim 7, wherein the conductive carbon material, that may have a fiber and / or sphere shape, is any one or a combination of the following materials: N doped carbon, acetylene black, activated carbon, graphite acetylene black, or, preferably, 10-15wt% N doped carbon spheres.

9. The AZIB according to claim 7 or 8, wherein the additive materials comprise any one, or a combination of, the following materials: bentonite, polymer gel, cellulose fibers and electrolytes, and is preferably bentonite 3-5wt%.

10. The AZIB according to any preceding claim, wherein the cathode comprises, and optionally consists of, a free-standing film; and the free-standing film comprises the manganese oxide(s) that may be MnCh powders, the carbon materials, and fibrous polytetrafluoroethylene (PTFE), and the free-standing film has a preferred thickness of 100-150 pm, and a more preferred thickness of 130-150 pm.

11. The AZIB according to any preceding claim, wherein the cathode comprises, and optionally consists of: the manganese oxides; the carbon materials that are conductive carbon materials; additive materials, such as bentonite; andPTFE as a binder; andthe mixed mass ratio of the manganese-based oxides, conductive carbon materials, additive materials and PTFE is 70%-95%: 0.5%-20%: 3%-10%.

12. The AZIB according to claim 11, wherein the conductive carbon materials are any one or a combination of the following materials: N doped carbon, acetylene black, activated carbon that preferably has a fiber and / or sphere shape, graphite acetylene black, and is preferably 10-15wt% N doped carbon spheres.

13. The AZIB according to claim 11 or 12, wherein the additive materials comprise any one, or a combination of, the following materials: bentonite, polymer gel, cellulose fibers and electrolytes, and is preferably bentonite 3-5wt%.

14. The AZIB according to any preceding claim, wherein the Zn ion separator comprises a free-standing zinc ion separator film.

15. The AZIB according to claim 14, wherein the free-standing zinc ion separator film comprises, and optionally consists of, a pre-zincified polyphenylene sulfide powder, cellulose fiber, and PTFE powder with a weight ratio of 80-95%: 2-5%: 3-6%, and a preferred ratio of 90-92%: 3-4%: 4-5%.

16. The AZIB according to claim 14 or 15, wherein the thickness of the zinc ion separator film is in the range of about 13-45 pm, and preferably about 15-20 pm.

17. The AZIB according to any of claims 14 to 16, wherein the porosity of the zinc ion separator film is less than 2-5%, and preferably less than 3%.

18. The AZIB according to any preceding claim, wherein the solid Zn ion separator comprises, and optionally consists of, a multilayer structure of Polyethylene (PE) / Polyphenylene sulfide (PPS) / cellulose layers; andY1 wherein, optionally, the thickness of the PE and cellulose layers are in a range of 5-9 pm, and preferably in a range of 5-6 pm; and wherein, optionally, the PE and cellulose films are porous and the PPS film is nonporous.

19. A method of manufacturing the anode of an aqueous Zn ion battery, AZIB, the method comprising: preparing a mixture comprising Zn powders, conductive carbon powders and PTFE powders; adding alcohol and water to the mixture; drawing the mixture in a supersonic dry airflow to orientate and fiberize PTFE; centrifuging the mixture to remove excess liquid; and passing the mixture through a roller press so as to form a self-supporting film at room temperature.

20. The method according to claim 19, wherein the anode is the anode of an AZIB according to any of claims 1 to 18.

21. A method of manufacturing the cathode of an aqueous Zn ion battery, AZIB, the method comprising: preparing a mixture comprising manganese oxide powders, conductive carbon powders and PTFE powders; adding alcohol and water to the mixture; drawing the mixture in a supersonic dry airflow to orientate and fiberize PTFE; centrifuging the mixture to remove excess liquid; and passing the mixture through a roller press so as to form a self-supporting film at room temperature.

22. The method according to claim 21, wherein the cathode is the cathode of an AZIB according to any of claims 1 to 18.

23. A method of manufacturing a free-standing zinc ion separator film of an aqueous Zn ion battery, AZIB, the method comprising: mixing pre-zincified polyphenylene sulfide powders, cellulose fibers, and polytetrafluoroethylene (PTFE) powders; drawing the mixture in a supersonic dry airflow so as to orientate constituents of the mixture; and hot pressing the mixture into a free-standing film at a temperature range of 120-150 °C, and preferably 130-145 °C; wherein the free-standing film preferably has a thickness in the range 10-20 pm, and more preferably 12-16 pm.

24. The method according to claim 22, wherein the zinc ion separator film is the solid Zn ion separator of an AZIB according to any of claims 1 to 18.

25. A method of manufacturing an aqueous Zn ion battery, AZIB, according to any of claims 1 to 18, the method comprising: manufacturing the anode of the AZIB according to the method of claim 19; manufacturing the cathode of the AZIB according to the method of claim 21 ; manufacturing the solid Zn ion separator of the AZIB according to the method of claim 23; and assembling the AZIB.

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